1. Field of the Invention
The present invention relates to a distributed feedback laser diode including a diffraction grating formed by electron beam lithography and a method of fabricating the distributed feedback laser diode.
2. Background Art
Japanese Patent Laid-Open No. 2005-353761 discloses a distributed feedback laser diode including a diffraction grating having a sawtooth profile at the interface between an InGaAsP light guiding layer and a p-type InP cladding layer.
There are cases where diffraction grating features are drawn on a resist by electron beam lithography and then a diffraction grating is formed using the diffraction grating features. Electron beam lithography enables the drawing of fine diffraction grating features, but has the problem that processing time increases in proportion to the area of the diffraction grating features.